- C. S. Hammond (New York) (1)
- C.F. Peters Corporation (Leipzig), 1929 (1)
- C.S. Hammond & Co (New York) (1)
- Chamber of Commerce (Austin) (1)
- Chicago Surface Lines (Chicago, Ill), 1929 (1)
- City Engineer (Watertown, N.Y) (1)
- Commissioner of Public Works (Woonsocket, R.I), 1930 (1)
- Covici-Friede (New York), 1929 (1)